1. Field of the Invention
The invention generally relates to an apparatus and method useful for the reattachment of a bone section removed during surgery and, more particularly, to a clamp and cable system for reattaching the dome portion of the greater trochanter to prevent migration of the removed bone section until it fuses to the remaining bone.
2. Description of the Related Art
Hip surgery often requires osteotomy of the dome portion of the greater trochanter to access the joint. Following such surgery it is important that the removed portion be clamped in place to promote efficient healing through fusion of the removed portion to the remainder of the femur.
Many surgeons simply reattach the removed trochanter section after implanting a hip prosthesis by wiring the section to the remainder of the trochanter. This has proved unsatisfactory because of forces that cause the section to shift or rotate when the patient is walking or raising from a seat. It is not uncommon for surgical wires to break because of the magnitude of such forces.
A trochanter reattachment system used in the past is known as the Dall-Miles system, described in U.S. Pat. No. 4,269,180. This system utilizes an H-shaped clamp which is held in place on the reattached bone section by teeth that engage the outer surface of the domed segment and others that are embedded. Cables are passed through holes in the bridge of the clamp and through holes drilled in the femur. The bridge of the clamp is crimped onto the cables to fix them in position.
The Dall-Miles system has experienced cable failure problems, which are believed to be caused by the sharp bends which the cables are forced to make as they exit the bridge of the clamp. Such failures result in the clamp loosening and tissue irritation caused by the frayed cable ends.
The Dall-Miles system is not particularly effective in providing rotational and vertical stability for the trochanter segment. Since the attachment cables must pass through the single bridge of the H-shaped clamp, the clamp can rotate about the bridge. Vertical stability is also lacking because the clamp is configured such that the cables must pass through the femur only in a single direction in the vicinity of the lesser trochanter.
Therefore, there is a perceived need for a device that can reliably reattach the greater trochanter to the femur following osteotomy, which provides maximum rotational and vertical stability, while minimizing the possibility of a failure resulting in loosening of the device or the necessity of its removal.